package jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCDemo7 {
    public static void main(String[] args) {
        try(
                Connection connection = DBUtil.getConnection();
        ){
            Statement statement= connection.createStatement();
            String sql = "SELECT COUNT(*)count "+
                    "FROM student s " +
                    "JOIN class c ON s.class_id = c.id " +
                    "WHERE c.name = '1年级1班 '";
            ResultSet rs = statement.executeQuery(sql);
            if(rs.next()){
                int count = rs.getInt("count");
                System.out.println("共"+count+"人");
            }
        }catch (SQLException e){
            e.printStackTrace();
        }


    }
}
